Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 4, 2013 at 05:20 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update November 2, 2013)] [Cycle 24 progress (last update November 2, 2013) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 2, 2013)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 2, 2013)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update November 3, 2013)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated November 2, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to unsettled on November 3. Solar wind speed at SOHO ranged between 348 and 437 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 143.5 (increasing 31.5 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 119.0. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.4). Three hour interval K indices: 23210021 (planetary), 23311121 (Boulder).

The background x-ray flux is at the class B6 level.

At the time of counting spots (see image time) spots were observed in 13 active regions in 2K resolution (SN: 272) and 8 active regions in 1K resolution (SN: 151) SDO images on the visible solar disk.

Region 11882 [S10W60] decayed slowly and quietly.
Region 11883 [N04W29] reemerged with a penumbra spot.
Region 11884 [S15W25] decayed quickly and has only minor polarity intermixing. C5+ flares: major M5.0/2B at 05:22 UTC.
Region 11887 [N20E08] developed quickly as new flux emerged. C and minor M class flares are possible.
Region 11888 [S13W72] was quiet and stable.
Region 11889 [S19E08] gained penumbral area, however, the region appears to be maturing.
Region 11890 [S11E65] is a large region capable of producing major M and X flares. There's a significant magnetic delta structure in the trailing penumbra.
C5+ flares: C9.9 at 16:28 UTC.

Spotted regions not numbered by SWPC:
S2798 [S22W27] decayed slowly and quietly.
S2802 [S09W01] was quiet and stable.
New region S2803 [N06E70] rotated into view with penumbra spots.
New region S2804 [N13W10] emerged with a penumbra spot.
New region S2805 [S25W16] emerged with penumbra spots.
New region S2806 [S10E25] emerged with penumbra spots.

Coronal mass ejections (CMEs)

November 1, 3: No obviously Earth directed CMEs were observed in LASCO or STEREO imagery.
November 2: A full halo CME was observed after 05h UTC, its source was backsided in a northern hemisphere active region (near the equator). Another impressive CME was observed later in the day after another backsided flare.

Coronal holes

Coronal hole history (since October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago

A recurrent coronal hole (CH592) was in an Earth facing positon on October 31-November 3.

Coronal hole map

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 4-6 due to weak coronal hole effects.

Coronal holes (1) Coronal mass ejection (2) M and X class flares (3)
     

1) Effects from a coronal hole could reach Earth within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability.

Active solar regions

(Click on image for 2K resolution) Compare to the previous day's image. 0.5K image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.

Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.

Active region Date numbered
detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlay
Comment
SWPC STAR SDO SWPC STAR Current Previous
2K 1K
11882 2013.10.23
2013.10.24
2 3 2 S10W60 0110 HAX CAO

 

11883 2013.10.26   1   N04W40 0003   AXX  

location: N04W29

11884 2013.10.26 27 25 12 S12W27 0240 EAC DAO

location: S15W25

11885 2013.10.26 6     S20W29 0180 CSO       part of AR 11884
11888 2013.10.27
2013.10.31
3 5 1 S14W74 0020 CRO BXO  
11886 2013.10.28
2013.10.29
      N14W78           plage
S2789 2013.10.29       N02W59           plage
11887 2013.10.29
2013.10.30
7 41 25 N20E09 0020 CRO DAC

area: 0150

S2791 2013.10.29       N13W44           plage
S2792 2013.10.30       S10E20           plage
S2796 2013.10.31       N05E32           plage
S2797 2013.10.31       S05W31           plage
S2798 2013.11.01   4   S22W27 0010   BXO  
11890 2013.11.01
2013.11.02
15 31 19 S10E62 0660 EHC EKC beta-gamma-delta

area: 1100

location: S11E65

11889 2013.11.02 13 21 10 S19E08 0050 DAO DAI beta-gamma

area: 0120

S2800 2013.11.02       S08E47         plage
S2802 2013.11.02   2 1 S09W01 0010   AXX  
S2803 2013.11.03   2 1 N06E70 0007   AXX    
S2804 2013.11.03   1   N13W10 0003   AXX    
S2805 2013.11.03   4   S25W16 0008   BXO    
S2806 2013.11.03   2   S09W01 0004   AXX    
Total spot count: 73 142 71  
Sunspot number: 143 272 151  (total spot count + 10 * number of spotted regions)
Weighted SN: 109 172 101  (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number): 86 95 83 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2011.11 153.5 (cycle peak) 96.7 (cycle peak) 61.1 (+1.2) 5.55
2012.02 106.5 32.9 66.9 (+1.4)
likely cycle 24 max
8.81
2012.07 133.9 66.5 57.8 (-1.1) 13.90
2012.08 115.4 63.0 58.2 (+0.4) 7.96
2012.09 122.9 61.4 58.1 (-0.1) 8.07
2012.10 123.3 53.3 58.6 (+0.5) 9.97
2012.11 121.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 40.8 59.6 (-0.1) 3.44
2013.01 127.1 62.9 58.7 (-0.9) 4.69
2013.02 104.3 38.0 58.4 (-0.3) 6.11
2013.03 111.3 57.9 57.5 (-0.9) 10.56
2013.04 124.8 72.4 57.9 (+0.4) 5.40
2013.05 131.4 78.7 (59.3 projected, +1.4) 9.73
2013.06 110.1 52.5 (59.7 projected, +0.4) 12.60
2013.07 115.5 57.0 (60.0 projected, +0.3) 9.47
2013.08 114.6 66.0 (60.3 projected, +0.3) 8.27
2013.09 102.6 36.9 (60.2 projected, -0.1) 5.23
2013.10  132.1 85.6 (58.7 projected, -1.5) 7.65
2013.10  143.6 (1) 12.0 (2A) / 120.3 (2B) / 82.3 (2C) (56.6 projected, -2.1) (4.2)

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official SIDC international sunspot number is typically 30-50% lower. 2B) Boulder SN current month average to date. 2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international Potsdam WDC ap indices.

This report has been prepared by Jan Alvestad. It is based on the analysis of data from whatever sources are available at the time the report is prepared. All time references are to the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.